Question juridique clé
Whether a revision ground existed under Art. 17 ATSG because the insured's hypothetical work capacity changed.
Solution extraite
A mere change in the hypothetical employment percentage is not enough; there must be a materially relevant change affecting the pension entitlement.
Motifs extraits
The health status was unchanged and only the assumed workload changed. That alone did not alter the pension entitlement under Art. 28 Abs. 2 IVG, so no revision ground existed.